There’s really no simple way of doing this. In the ACF core javascript, the new element is appended to the list, and I don’t really see a way of hooking into that easily. If this is a client’s request, the short answer is no. The long answer is yes, but it’ll cost them some $$$.
Basically you’d need to hijack what is natively done and things can get sticky from there. Or…. you can jump into the ACF core javascript files and change this: this.$list('values').append( html ) to this.$list('values').prepend( html ). But of course, that’ll only last until they update ACF, which is horrible idea.
